Eur. Phys. J. E (2011) 34: 125
https://doi.org/10.1140/epje/i2011-11125-5

Collective dynamics of colloids at fluid interfaces

¹ Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569, Stuttgart, Germany
² Institut für Physik, WA 331, Johannes Gutenberg Universität Mainz, 55099, Mainz, Germany
³ Física Teórica, Universidad de Sevilla, Apdo. 1065, 41080, Sevilla, Spain
⁴ Institut für Theoretische und Angewandte Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569, Stuttgart, Germany

^* e-mail: bleibel@mf.mpg.de

Received: 17 August 2011
Accepted: 26 October 2011
Published online: 24 November 2011

Abstract

The evolution of an initially prepared distribution of micron-sized colloidal particles, trapped at a fluid interface and under the action of their mutual capillary attraction, is analyzed by using Brownian dynamics simulations. At a separation given by the capillary length of typically 1mm, the distance dependence of this attraction exhibits a crossover from a logarithmic decay, formally analogous to two-dimensional gravity, to an exponential decay. We discuss in detail the adaptation of a particle-mesh algorithm, as used in cosmological simulations to study structure formation due to gravitational collapse, to the present colloidal problem. These simulations confirm the predictions, as far as available, of a mean-field theory developed previously for this problem. The evolution is monitored by quantitative characteristics which are particularly sensitive to the formation of highly inhomogeneous structures. Upon increasing the dynamics shows a smooth transition from the spinodal decomposition expected for a simple fluid with short-ranged attraction to the self-gravitational collapse scenario.